Circular knitting machine and bearing assembly for same

Abstract: A circular knitting machine is provided that has a bed member and a needle cylinder including a cylinder base rotatably mounted to the bed member. The knitting machine also has a bearing assembly positioned between the bed member and the cylinder base for rotatable mounting of the bed member to the cylinder base. In alternate embodiments, the bearing assembly preferably includes a first race ( 71 ) slidably connected to either the cylinder base or the bed member and a second race ( 72 ) connected to either the cylinder base or the bed member and positioned adjacent and spaced-apart from the first race ( 71 ). First and second tracks are respectively mounted to the first and second races, and bearings are positionally supported by and between the first and second tracks so that the cylinder base freely rotates about the bed member. A thermal-expansion compensator is preferably integrally formed with either the cylinder base or the bed member and is positioned closely adjacent the corresponding race respectively connected to either the cylinder base or the bed member. The compensator is adapted for compensating for thermal expansion in the cylinder base during heating and cooling thereof. The compensator preferably includes a flexible flange integrally formed with either the cylinder base or the bed member and positioned closely adjacent the corresponding race. The race positioned closely adjacent the flexible flange is preferably slidably connected to the corresponding cylinder base or bed member so that slidably movement of the corresponding race responsive to heating and cooling of the cylinder base thereby moves the flexible flange.

Description: Field Of The Invention This invention relates to a circular knitting machine, and more particularly to a circular knitting machine having a needle cylinder rotatably mounted to a bed member for rotation thereof about the bed member. Background Of The Invention Circular knitting machines are generally considered a high precision type of knitting machine. Some types of conventional circular knitting machines have a needle cylinder which includes a cylinder base. The cylinder base is conventionally seated in a generally L-shaped bed and is supported in a rotatable manner by a bearing assembly that is positioned between the cylinder base and the L-shaped bed. The bearing assembly conventionally includes pairs of annular wire tracks and a plurality of ball bearings mounted between the pairs of wire tracks. When this type of circular knitting machine is in operation, the needle cylinder increases in temperature particularly because the knitting tools which are guided in the needle cylinder perform rapid upward and downward movements. As the temperature in the needle cylinder increases, the heat formed therein is transferred from the needle cylinder to the cylinder base causing thermal expansion in and around the cylinder base. When the machine is stopped, however, the ambient atmosphere often cools the cylinder base. A distortion occurs which is caused by these temperature changes, i.e., temperature differential. This distortion substantially affects the machine's accuracy. In one attempt to solve this problem in this type of circular knitting machine, as described in U.S. Patent No. 4,489,573 by Engelfried et al. titled " Circular Knitting Machine, " the circular knitting machine has an elastic support flange that moves the position of one of the circular wire tracks of a pair thereof responsive to pressure fluctuation (i.e., caused by the thermal expansion of the cylinder base) between the circular wire track and ball bearings. Another non-elastic support flange of the other corresponding circular wire track is anchored in such a way as to cooperate with the elastic support flange. The spacing between the wire tracks of the pair is increased and the wire tracks slide outwardly on the ball bearings. The thermal expansion of the cylinder base is thus compensated. In the above prior art type of circular knitting machine, however, a preload or pretension is applied to the bearing assembly in order to maintain the machine accuracy. This results in an increased machine torque and, hence, an excessive load to the bearing assembly. This excessive load may cause damage to the bearing assembly thereby inhibiting the operational performance of the circular knitting machine. Moreover, the elastic support flange for holding one of the circular wire tracks also must be thin enough to obtain elasticity; this tends to result in machining distortion which also makes it difficult to obtain a high level of accuracy. Object And Summary Of The Invention An object of the present invention is to provide a more accurate circular knitting machine by compensating for thermal expansion in and around a cylinder base of a needle cylinder of the machine. It is also an object of the present invention to provide a circular knitting machine that does not apply an excessive load or tension to a bearing assembly positioned between a bed member and a cylinder base of a needle cylinder rotatably mounted to the bed member. More particularly, the invention meets these and other objects by providing a circular knitting machine that has a bed member and a needle cylinder including a cylinder base rotatably mounted to the bed member. The knitting machine also has a bearing assembly positioned between the bed member and the cylinder base for rotatable mounting of the bed member to the cylinder base. In alternative embodiments, the bearing assembly preferably includes a first race slidably connected to either the cylinder base or the bed member and a second race connected to either the cylinder base or the bed member and positioned adjacent and spaced-apart from the first race. First and second tracks are respectively mounted to the first and second races, and bearings are positionally supported by and between the first and second tracks so that the cylinder base freely rotates about the bed member. Thermal-expansion compensating means is preferably integrally formed with either the cylinder base or the bed member and is positioned closely adjacent the race respectively connected to either the cylinder base or the bed member. The compensating means is adapted for compensating for thermal expansion in the cylinder base during heating and cooling thereof. The compensating means preferably includes a flexible flange integrally formed with either the cylinder base or the bed member and positioned closely adjacent the corresponding race. The race positioned closely adjacent the flexible flange is preferably slidably connected to the corresponding cylinder base or bed member so that slidable movement of the corresponding race responsive to heating and cooling of the cylinder base thereby moves the flexible flange. This configuration of the circular knitting machine and the bearing assembly positioned therein advantageously lessens the tension on the bearing assembly and provides a more accurate circular knitting machine by compensating for thermal expansion in and around the cylinder base. In other words, the bearing assembly does not require an excessive load or tension for smooth and accurate operation. Also, the present invention includes a bearing assembly adapted for connecting to and positioning between a bed member and a base of a needle cylinder of a circular knitting machine. In alternate embodiments, the bearing assembly preferably has a first non-flexible race adapted to slidably connect to either a base of a needle cylinder or a bed member of a circular knitting machine and a second non-flexible race adapted to connect to either a base of a needle cylinder or a bed member of a circular knitting machine. The second race is positioned adjacent and spaced-apart from the first race. The first and second races each have an opposingly facing channel positioned therein. First and second spaced-apart pairs of tracks are respectively positioned in the channel of the first race and in the channel of the second race. A plurality of bearing balls preferably are positionally supported by and between the first and second pairs of tracks so that the base of the needle cylinder freely rotates about the bed member. Thermal-expansion compensating means is integrally formed with either the base of the needle cylinder or the bed member and positioned closely adjacent either the first or second corresponding race for compensating for thermal expansion in the base during heating and cooling thereof. The compensating means preferably includes a connector slidably connecting either the first or second race to either the base or the bed member and a flexible flange integrally formed with the base and positioned closely adjacent the second race so that the second race slidably moves responsive to heating and cooling of the base of the needle cylinder and thereby moves the flexible flange. The thermal expansion of the cylinder base is therefore indirectly compensated by the position of and the movement of the flexible flange. Brief Description Of The Drawings Some of the objects and advantages of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings in which: Figure 1 illustrates a side sectional view of portions of a circular knitting machine having a needle cylinder supported by a cylinder base rotatably mounted to a bed member according to a first embodiment of the invention; Figure 2 illustrates an enlarged sectional view of a bearing assembly of Figure 1 according to a first embodiment of the circular knitting machine of the present invention; Figure 3 illustrates an enlarged perspective view of a connecting pin for a bearing assembly of a circular knitting machine according to a first embodiment of the present invention; Figure 4 illustrates a sectional view of a first race slidably connected to a cylinder base of a circular knitting machine taken along line 4-4 of Figure 2; Figure 5 illustrates a fragmentary perspective view of an annular wire track and a stopping member engaging the wire track and mounted to a first race according to a first embodiment of the present invention; Figure 6 illustrates a sectional view of an annular wire track and a stopping member taken along line 6-6 of Figure 5 according to a first embodiment of the present invention; Figure 7 illustrates a sectional view of an annular wire track and a stopping member taken along line 7-7 of Figure 5 according to a first embodiment of the present invention; Figure 8 illustrates a fragmentary sectional view of a second embodiment of a bearing assembly having non-circular wire tracks according to the present invention; Figure 9 illustrates an enlarged fragmentary sectional view of a third embodiment of a bearing assembly having bearing balls of differing diameters according to the present invention; Figure 10 illustrates a side sectional view of a fourth embodiment of a bearing assembly positioned between a cylinder base and a bed member of a circular knitting machine according to the present invention; Figure 11 illustrates a side sectional view of a fifth embodiment of a bearing assembly positioned between a cylinder base and a bed member of a circular knitting machine according to the present invention; Figure 12 illustrates a side sectional view of a sixth embodiment of a bearing assembly positioned between a cylinder base and a bed member of a circular knitting machine according to the present invention; Figure 13 illustrates a side sectional view of a seventh embodiment of a bearing assembly positioned between a cylinder base and a bed member of a circular knitting machine according to the present invention; Figure 14 illustrates a side sectional view of an eighth embodiment of a bearing assembly positioned between a cylinder base and a bed member according to the present invention; and Figure 15 illustrates a side sectional view of a ninth embodiment of a bearing assembly positioned between a cylinder base and a bed member according to the present invention. Detailed Description Of A Preferred Embodiment The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which typical preferred embodiments are shown. This invention, however, may be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. Figure 1 illustrates a side sectional view of a circular knitting machine ( 20 ) according to a first embodiment of the present invention. The circular knitting machine ( 20 ) has a frame which includes a yarn-feed frame support member ( 25 ) and a sinker frame support member ( 26 ). As understood by those skilled in the art, the yarn-feed frame support member ( 25 ) supports a yarn-feed assembly ( 29 ) as illustrated. The sinker frame support member ( 26 ) is preferably connected to a bed member ( 30 ) by a ring plate ( 27 ) and a fastener, such as a screw ( 28 ). The sinker frame support member ( 26 ) also likewise supports a sinker assembly which conventionally includes sinkers ( 21 ) and sinker cams ( 22 ) positioned to operationally engage the sinkers ( 21 ). The sinkers ( 21 ) and the sinker cams ( 22 ) are supported on the sinker frame support member ( 26 ) by a sinker support ring ( 23 ) and a sinker ring plate ( 25 ) respectively connected to the sinker cams ( 22 ) and the sinker frame support member ( 26 ) as illustrated. The circular knitting machine ( 20 ) also includes a needle cylinder ( 60 ) rotatably mounted on a cylinder base ( 40 ). The needle cylinder ( 60 ) has vertical grooves in the outer periphery thereof in which there are slidably mounted needles ( 61 ). Butts ( 62 ) on the needles ( 61 ) operationally engage needle cams ( 64 ). The needle cams ( 64 ) are mounted on a cam plate member ( 65 ) which in turn is mounted on a cam support ring ( 67 ) by a fastener, such as a screw ( 62 ). The present invention is more particularly directed to the needle cylinder ( 60 ) and the cylinder base ( 40 ) of the circular knitting machine ( 20 ) and the accuracy problems associated with a conventional circular knitting machine when in operation. The construction and operational characteristics of the yarn-feed assembly ( 29 ), the sinkers ( 21 ), the needle cylinder ( 60 ), and the needles ( 61 ) are known to those skilled in the art. Accordingly, for brevity purposes, the remaining description will be directed to the needle cylinder ( 60 ), the cylinder base ( 40 ), and the rotatable mounting of the cylinder base ( 40 ) on the bed member ( 30 ) of the circular knitting machine ( 20 ). As also illustrated in Figures 1 and 2, the cylinder base ( 40 ) of the needle cylinder ( 60 ) is preferably rotatably mounted to the bed member ( 30 ). The bed member ( 30 ) is preferably supported by the frame of the circular knitting machine ( 20 ), has a generally L-shape as illustrated, and includes a bed body ( 31 ) and a generally horizontal extending bed leg member ( 35 ). The cylinder base ( 40 ) likewise preferably has a base body ( 45 ) and a generally horizontal extending base leg member ( 41 ) preferably mounted in a rotatable manner to the bed leg member ( 35 ) as illustrated so that the cylinder base ( 40 ) rotates about the bed member ( 30 ). The needle cylinder ( 60 ) is preferably secured to the cylinder base body ( 45 ) by means of fasteners such as a bolt or screw ( 62 ). The cylinder base leg member ( 45 ) also has an engraved gear ( 42 ) connected to an outer end thereof and is preferably driven by a drive source positioned outside of the knitting machine ( 20 ) such as through a pinion (not shown). When a circular knitting machine ( 20 ) is in operation, the needle cylinder ( 60 ) often increases in temperature particularly because the needles ( 61 ) mounted in the needle cylinder ( 60 ) performs rapid upward and downward movements. As the temperature in the needle cylinder ( 60 ) increases, the heat formed therein is transferred from the needle cylinder ( 60 ) to the cylinder base ( 40 ) causing thermal expansion in and around the cylinder base ( 40 ). When the machine ( 20 ) is stopped, however, the ambient atmosphere often cools the cylinder base ( 40 ). A distortion often occurs which is caused by these temperature changes, i.e., temperature differential. This distortion substantially affects the machine's accuracy. To address this problem, a bearing assembly ( 70 ) according to the present invention preferably connects to, is integrally formed with, and is positioned between the cylinder base ( 40 ) and the bed member ( 30 ) as illustrated by the various embodiments in Figures 1-15. The bearing assembly ( 70 ) is adapted and constructed to particularly compensate for thermal expansion in and around the cylinder base ( 40 ) by including means for compensating for this thermal expansion. On a lower end of the base leg member ( 45 ) of the cylinder base ( 40 ), the bearing assembly ( 70 ) has a portion of thermal expansion compensating means illustrated in the form of a flexible annular base flange ( 43 ) which is preferably integrally formed with the cylinder base ( 40 ). Although preferably relatively thin, the desired thickness of this flexible annular base flange ( 43 ) may vary and fluctuate according to the material of the base flange ( 43 ) and/or other factors. An optimum value for this thickness, therefore, is preferably experimentally determined for the machines ( 20 ). Outside and adjacent the flexible annular base flange ( 43 ), the bearing assembly also preferably includes a first non-flexible annular race ( 71 ). The first race ( 71 ) is preferably slidably connected to the base leg member ( 45 ) and is positioned closely adjacent the flexible annular base flange ( 43 ). Opposite the first race ( 71 ), a second non-flexible annular race ( 72 ) is preferably formed integral with the bed member ( 30 ) and extends upwardly from the bed leg member ( 35 ). The bearing assembly ( 80 ) also preferably includes a plurality of annular wire tracks ( 81a - 81d ), i.e., four wire tracks arranged in opposing first and second pairs as illustrated, and a plurality of bearing balls ( 83 ) positioned between the wire tracks ( 81a - 81d ). Although the first and second pairs of tracks are described as wire tracks, it will be understood by those skilled in the art that these tracks may be formed of various metals and alloys thereof as well as various polymeric materials and the like. Figures 2-4 also illustrate the connecting of the first race ( 71 ) to the cylinder base ( 40 ). The configuration of the first race ( 71 ) and the connecting of the race ( 71 ) to the cylinder base ( 40 ) also form portions of the thermal expansion compensating means of the bearing assembly ( 70 ). The cylinder base ( 40 ) and the first race ( 71 ) are slidably connected to each other in a separable manner by means of a plurality of connecting pins ( 75 ) (as best shown in Figures 2 and 3). Figure 4 illustrates a sectional view of the cylinder base ( 40 ) and the first race ( 71 ) slidably connected thereto taken along line 4-4 of Figure 2. The first race ( 71 ) is detachably connected to the cylinder base ( 40 ) so that heat is not easily transmitted from the cylinder base ( 40 ) to the first race ( 71 ). As illustrated in Figure 3, each of the connecting pins ( 75 ) preferably has a cylindrical upper end portion ( 75a ) and a lower end portion having a first pair of relatively flat and parallel sides ( 75b ), i.e., cut-away portions, and a second pair of arcuate sides ( 75c ). The base leg member ( 41 ) of the cylinder base ( 40 ) preferably has a bore positioned therein, and the first race ( 71 ) likewise has a bore positioned therein. These bores preferably have a generally similar-sized circumference and are preferably positionally aligned so that the upper portion ( 75b ) of the connecting pin ( 75 ) is positioned within the bore of the base leg member ( 41 ) and the lower portion is positioned within the bore of the first race ( 71 ). The lower portion of the connecting pin ( 75 ) also preferably has a smaller circumference than the upper portion ( 75a ). The connecting pins ( 75 ) are therefore installed in such a way as to provide radial spaces ( 75d ) as best illustrated in Figure 4. Preferably surrounding the parallel and arcuate sides ( 75b, 75c ) of the lower portion of the pin ( 75 ), the first race ( 71 ) also provides a small gap or slightly enlarged portion of the bore illustrated by the circle surrounding the pin ( 75 ). This small gap in combination with the radial spaces ( 75d ) allows the first race ( 71 ) to slidably move inward when the cylinder base ( 40 ) expands by heat. Because the cylinder base ( 40 ) is connected by means of the connecting pins ( 75 ), it rotates together with the first race ( 71 ). Figure 2 also illustrates that the bearing assembly ( 70 ) preferably has a plurality of bearing balls ( 83 ) and annular wire tracks ( 81a, 81b, 81c, 81d ). The bearing balls ( 83 ) are supported by the annular wire tracks ( 81a - 81d ) and preferably form first and second pairs. A first pair of the annular wire tracks ( 81a, 81b ) is accommodated within a concave groove or channel ( 73 ) of the first race ( 71 ), and the other pair of annular wire tracks ( 81c, 81d ) is accommodated within a concave groove or channel ( 74 ) of the second race ( 72 ) respectively as illustrated. The contact points between the bearing balls ( 83 ) and the annular wire tracks ( 81a - 81d ) are preferably chamfered (not shown) so as to accommodate the arcuate portions of the bearing balls ( 83 ). The second race ( 72 ) also preferably includes a body portion integrally formed with the bed leg member ( 35 ) of the bed member ( 30 ). The body portion has a lower flange positioned along a lower end of the channel ( 74 ) of the second race ( 72 ), and an upper flange member ( 77 ) is preferably mounted with a fastener such as a screw ( 76 ) for spacing or gap adjustment of the annular wire tracks ( 81c, 81d ). Portions of the upper flange member ( 77 ) are positioned along the upper end of the channel ( 74 ). The fastener is adapted for adjusting the position of the second pair of wire tracks ( 81c, 81d ) within the channel ( 74 ). In alternate embodiments of a bearing assembly ( 70 ), such as illustrated in Figures 13-14, the fastener ( 176, 276 ) may also extend to and through a body portion of the second race ( 172, 272 ) and extend to and through the bed leg member ( 135, 235 ) of the bed member ( 30 ) for providing easier access to adjustably position the second pair of wire tracks ( 81c, 81d ) and the spacing therebetween, i.e., gaps. In these embodiments, the fasteners ( 176, 276 ) are illustrated in the form of a threaded bolt which screws into a threaded portion formed in the lower portion of the bed ( 30 ). The bolt ( 176, 276 ) is also positioned through the upper flange member ( 177, 277 ) and is fastened with a nut. The gaps are preferably adjusted by loosening the nut and rotating a lower end of the bolt. As best illustrated in Figures 5-7, the bearing assembly ( 70 ) also preferably includes stopping means respectively mounted to the first and second races ( 71, 72 ) and contactingly engaging each of the wire tracks ( 81a - 81d ). The stopping means is illustrated in the form of two opposing ends of the annular wire tracks ( 81a - 81d ). Each wire track ( 81a - 81d ) preferably has a relatively flat first end ( 81e ) of generally the same circumference and shape as the respective wire track ( 81a - 81d ) and a cut-away portion ( 81f ) on a second end. Between the first end ( 81e ) and the cut-away portion ( 81f ) of the second end, a lower end portion of an engaging pin ( 84 ) contactingly engages therewith. An upper end portion of the engaging pin ( 84 ) is mounted to a portion ( 71a ) of the race that accommodates the annular wire tracks ( 81a - 81d ) such as the first race ( 71 ) illustrated. Therefore, a sliding motion of the annular wire tracks ( 81a - 81d ) which is possibly generated along with the rotation of the machine ( 20 ) (indicated by the arrow in Figure 7) is stopped by the engaging pin ( 84 ). According to the thermal expansion compensating means, i.e., thermal expansion compensator, of the first embodiment of the present invention shown in Figures 1-7 above, the heat of the needle cylinder ( 60 ) that occurs during the operation of the knitting machine ( 20 ) is transmitted to the cylinder base ( 40 ) causing it to thermally expand. The thermal expansion of the cylinder base ( 40 ) is inhibited by the second non-flexible race ( 72 ) of the bearing assembly ( 70 ). The expansion of the cylinder base ( 40 ) thus inhibited then presses the first race ( 71 ) inward responsive thereto. The pressed first race ( 71 ) slidably moves about the connecting pins ( 75 ) responsive to the heating and cooling of the cylinder base ( 40 ) and then distorts the flexible annular base flange ( 43 ) of the cylinder base ( 40 ) inward. This distortion compensates for the thermal expansion of the cylinder base ( 40 ). This configuration and construction of the first non-flexible race ( 71 ) and the second non-flexible race ( 72 ) of the bearing assembly ( 70 ) of the present invention helps maintain the accuracy of the circular knitting machine ( 20 ) by indirectly compensating for the thermal expansion in and around the cylinder base ( 40 ). This configuration also lessens the load on the bearing assembly ( 70 ). In other words, the bearing assembly ( 70 ) does not require an excessive load or tension for smooth and accurate operation. Figure 8 illustrates another embodiment of a bearing assembly ( 70 ) of a circular knitting machine according to the present invention. Instead of the previously described annular wire tracks ( 81a - 81d ) having circular cross-sections, the wire tracks ( 81a' - 81d' ) may have a non-circular cross-section such as the rectangular cross-sections illustrated, as well as others. The wire tracks ( 81a' - 81d' ) of this embodiment also preferably have chamfered portions that surface-contact the bearing balls ( 83 ) positioned therebetween. Figure 9 illustrates yet another embodiment of a bearing assembly ( 70 ) of a circular knitting machine according to the present invention. The bearing assembly ( 70 ) in this embodiment has bearings in the form of bearing balls ( 83a',83b' ) of different diameters positioned between the pair of tracks ( 81a - 81d ), and arranged alternately so as to minimize collisions between neighboring bearing balls ( 83a',83b' ). Figures 10-12 and 15 illustrate additional embodiments of a bearing assembly ( 70 ) of a circular knitting machine ( 20 ) according to the present invention. Like elements in these various embodiments of the bearing assembly ( 70 ) according to the present invention have been designated with prime ( ' ) or double-prime ( '' ) notation throughout. Figure 10 illustrates a side sectional view of a bearing assembly ( 70 ) according to a fourth embodiment of the present invention. The fourth embodiment differs from the first embodiment in that the fourth embodiment preferably has a first annular race ( 71' ) that is provided with a flexible annular flange ( 71b' ) and a cylinder base ( 40 ) that is provided with a non-flexible annular flange ( 43a' ), i.e., corresponds to the flexible annular flange ( 43' ) of the first embodiment, that abuttingly engages the first race ( 71' ). The first race ( 71' ) according to this embodiment is wider than the first race ( 71 ) of the first embodiment shown in Figures 1-2. In Figure 10, the first race ( 71' ) is provided with a second concave groove or channel ( 79 ) extending downwardly from the base leg member ( 41 ) of the cylinder base ( 40 ) as illustrated and positioned between the flexible annular flange ( 71b' ) and the connecting pins ( 75 ). When the pressure from the thermally expanding cylinder base ( 40 ) is applied, the first race ( 71' ) slidably moves about the connecting pin ( 75 ) and presses against the non-flexible flange ( 43' ) of the cylinder base ( 40 ). This pressure against the non-flexible flange ( 43' ) then causes the flexible annular flange ( 71b' ) to responsively distort inward toward the second channel ( 79 ) thereby absorbing the thermal expansion of the cylinder base ( 40 ). The second race ( 72 ) and the connecting pins ( 10 ) are preferably of the same configurations as those in the first embodiment. Figures 11 and 12 respectively illustrate side sectional views of a bearing assembly ( 70 ) according to fifth and sixth embodiments of the present invention. These embodiments differ from the first and fourth embodiments in that these embodiments illustrate a relatively switched mounting position of the first and second races ( 71, 72 ) of the first and fourth embodiments. In these embodiments, the first races ( 71'' ) each have a generally similar configuration and are integrally formed with the cylinder base ( 40 ) in a similar manner as the second races ( 72 ) of the first and fourth embodiments. The second races ( 72', 72'' ), however, are slidably connected to the bed member ( 30 ) in a similar manner as the first races ( 71, 71' ) of the first and fourth embodiments. A flexible annular flange ( 39 ) is preferably integrally formed with the bed leg member ( 35' ) in the fifth embodiment and a non-flexible annular flange ( 39' ) is integrally formed with the bed leg member in the sixth embodiment. The portions of the bearing assembly ( 70 ) of these embodiments are generally the same as the first and fourth embodiments and are not described further for brevity purposes. In other words, the relative positions of the first race ( 71, 71' ), the second race ( 72 ), and the flexible annular flange ( 43 ) of the first and fourth embodiments are respectively switched or are in opposite positions from these fifth and sixth embodiments. Figures 14 and 15 respectively illustrate side sectional views of a bearing assembly ( 70 ) according to eighth and ninth embodiments of the present invention. In the eighth and ninth embodiments, the second races ( 272, 372 ) of the bearing assembly ( 70 ) have a different construction as illustrated. The second races ( 272, 372 ) of these embodiments have an upper flange member ( 277, 377 ) which includes a generally L-shaped section so that the body portion of the second race ( 272, 372 ) is relatively thinner than the second races ( 72, 72', 72'', 172 ) of the other embodiments. As with other embodiments, the upper flange member ( 277, 377 ) of the eighth and ninth embodiments has a fastener ( 276, 376 ) that extends through the upper flange member ( 277, 377 ) and may extend only into the bed leg member ( 335 ) or may extend through the bed leg member ( 235 ) of the bed member ( 30 ) as illustrated. In the drawings and specification, there have been disclosed typical preferred embodiments of the invention, and although specific terms are employed, the terms are used in a descriptive sense only and not for purposes of limitation. The invention has been described in considerable detail with specific reference to these various illustrated embodiments. It will be apparent, however, that various modifications and changes can be made within the scope of the invention as described in the foregoing specification and as defined in the appended claims.

Claims: A circular knitting machine (20), comprising: a bed member (30); a needle cylinder (60) including a cylinder base (40) rotatably mounted to said bed member (30); a bearing assembly (70) positioned between said bed member (30) and said cylinder base (40) for rotatable mounting of said bed member (30) to said cylinder base (40), said bearing assembly (70) including a first race (71; 71") connected to said cylinder base (40) and a second race (72; 72') connected to said bed member (30) and positioned adjacent and spaced-apart from said first race, wherein either said first race (71) is slidably connected to said cylinder base (40) or said second race (72') is slidably connected to said bed member (30), first (81a, 81b) and second (81c, 81d) tracks respectively mounted to said first (71) and second (72) races, and bearings (83) positionally supported by and between said first (81a, 81b) and second (81c, 81d) tracks so that cylinder base (40) freely rotates about said bed member (30); and thermal-expansion compensating means either integrally formed with said cylinder base (40) and positioned closely adjacent said first race (71) for compensating for thermal expansion in said cylinder base (40) during heating and cooling thereof, said compensating means including a flexible base flange (43) integrally formed with said cylinder base (40) and positioned closely adjacent said first race (71) so that slidable movement of said first race (71) responsive to heating and cooling of said cylinder base (40) thereby moves said flexible base flange (43) or integrally formed with said bed member (30) and positioned closely adjacent said second race (72') for compensating for thermal expansion in said cylinder base (40) during heating and cooling thereof, said compensating means including a flexible bed flange (39) integrally formed with said bed member (30) and positioned closely adjacent said second race (72') so that slidable movement of said second race (72') responsive to heating and cooling of said cylinder base (40) thereby moves said flexible bed flange (39). A circular knitting machine (20) as defined in claim 1, wherein said thermal expansion compensating means further comprises a connector (75) slidably connecting said cylinder base (40) and said first race (71) so that said first race (71) slidably moves about said connector (75) responsive to heating and cooling of said cylinder base (40). A circular knitting machine (20) as defined in claim 1, wherein said thermal expansion compensating means further comprises a connector (75') slidably connecting said bed member (30) and said second race (72') so that said second race (72') slidably moves about said connector (75') responsive to heating and cooling of said cylinder base (40). A circular knitting machine (20) as defined in claim 2, wherein said cylinder base (40) and said first race (71) each have bores therein, each of said respective bores being positionally aligned and having a generally similar-sized circumference, and wherein said connector (75) of said thermal compensating means comprises a connecting pin having an upper end portion (75a) and a lower end portion (75b, 75c), said upper end portion (75a) being positioned within said bore of said cylinder base (40) and said lower end portion being positioned within said bore of said first race (71), said lower end portion of said connecting pin (75) having a smaller circumference than said upper end portion (75a) for providing slidable movement of said first race (71) about said connecting pin (75). A circular knitting machine (20) as defined in claim 3, wherein said bed member (30) and said second race (72) each have bores therein, each of said respective bores being positionally aligned and having a generally similar-sized circumference, and wherein said connector (75') of said thermal compensating means comprises a connecting pin (75') having an upper end portion (75a') and a lower end portion (75b', 75c'), said upper end portion (75a') being positioned within said bore of said bed member (30) and said lower end portion (75b', 75c') being positioned within said bore of said second race (72'), said lower end portion (75b', 75c') of said connecting pin (75) having a smaller circumference than said upper end portion (75a) for providing slidable movement of said second race (72') about said connecting pin (75'). A circular knitting machine (20) as defined in claim 1, wherein each of said first and second races (71, 72) has an opposingly facing channel (73, 74) formed therein for mounting said first (81a, 81b) and second (81c, 81d) tracks, and wherein said second race (72) includes a body portion integrally formed with said bed member (30) and having a lower flange, an upper flange member (77) detachably connected to said body portion, said lower flange and portions of said upper flange member (77) being respectively positioned along upper and lower ends of said channel (74) for retaining said second tracks (81c, 81d) therein, and a fastener (76) adjustably connecting said upper flange member (77) to said body portion. A circular knitting machine (20) as defined in claim 1, wherein each of said first (71") and second (72') races has an opposingly facing channel (73, 74) formed therein for mounting of said first (81a, 81b) and second (81c, 81d) tracks, and wherein said first race (71") includes a body portion integrally formed with said cylinder base (40) and having a lower flange, an upper flange member (77') detachably connected to said body portion, said lower flange and portions of said upper flange member (77') being respectively positioned along upper and lower ends of said channel (73) for retaining said first tracks (81a, 81b) therein, and a fastener (76') adjustably connecting said upper flange member (77') to said body portion. A circular knitting machine (20) as defined in claim 1, wherein said bearing assembly (70) further comprises stopping means (85) connected to said first and second races (71, 72) and positioned closely adjacent an contactingly engaging said first (81a, 81b) and second (81c, 81d) tracks for stopping rotation of said first (81a, 81b) and second (81c, 81d) tracks. A circular knitting machine (20) as defined in claim 1, wherein at least two of said plurality of bearing balls (83a, 83b) have different diameters. A circular knitting machine (20) as defined in claim 1, wherein said first and second tracks each comprise a pair of annular wire tracks (81a'-81d') having a non-circular cross-section. A circular knitting machine (20) as defined in claim 1, comprising: a frame; a bed member (30) mounted to said frame and having a bed leg member (35) extending in a generally horizontal plane; a needle cylinder (60) including a cylinder base (40) having a base leg member (41) extending in a generally horizontal plane and rotatably mounted to said bed leg member (35); a bearing assembly (70) positioned between said base leg member (41) and said bed leg member (35) and adapted for rotatable mounting of said base leg member (41) to said bed leg member (35), said bearing assembly (70) including a first annular race (71') slidably connected to and extending downwardly from said base leg member (41) and a second annular non-flexible race (72) connected to and extending upwardly from said bed leg member (35) and positioned adjacent and spaced-apart from said first race (71'), said first and second annular races (71, 72) each having an opposingly facing channel (73, 74) positioned therein, first and second spaced-apart pairs of annular wire tracks (81a-81d) respectively positioned in said channel (73) of said first race (71') and in said channel (74) of said second race (72), and a plurality of bearing balls (83) positionally supported by and between said first and second pairs of annular wire tracks (81a-81d) so that said cylinder base (40) freely rotates about said bed member (30); and thermal-expansion compensating means integrally formed with said first race (71') and said cylinder base (40) for compensating for thermal expansion in said cylinder base (40) during heating and cooling thereof, said compensating means including a connector (75) slidably connecting said first race (71') to said base leg member (41), a non-flexible base flange (43') integrally formed with said base leg member (41), extending downwardly therefrom and positioned closely adjacent and abuttingly engaging said first race (71'), a channel (79) formed in said first race (71') and extending downward from said base leg member (41), and a flexible race flange (71b') positioned between said downward extending channel (79) and said non-flexible base flange (43) so that said first race (71') slidably moves about said connector (75) responsive to heating and cooling of said cylinder base (40) and thereby moves said flexible race flange (71b'). A circular knitting machine (20) as defined in claim 11, wherein said second non-flexible race (72) includes a body portion integrally formed with said bed leg member (35) and having a lower flange, an upper flange member (77) detachably connected to body a portion, said lower flange and portions of said upper flange member (77) being respectively positioned along upper and lower ends of said channel (74) for retaining said second pair of wire tracks (81c, 81d) therein, and a fastener (76) adjustably connecting said upper flange member (77) to said body portion. A circular knitting machine (20) as defined in claim 11, wherein said connector (75) of said thermal compensating means is a pin comprising an upper end portion (75a) and a lower end portion (75b, 75c), said upper end portion (75a) being positioned within said cylinder base (40) and said lower end portion positioned within said first race (71), said lower end portion (75b, 75c) having a smaller circumference than said upper end portion (75a). A circular knitting machine (20) as defined in claim 1, comprising: a frame; a bed member (30) mounted to said frame and having a bed leg member (35') extending in a generally horizontal plane; a needle cylinder (60) including a cylinder base (40) having a base leg member (41') extending in a generally horizontal plane and rotatably mounted to said bed leg member (35'); a bearing assembly (70) positioned between said base leg member (41') and said bed leg member (35) and adapted for rotatable mounting of said base leg member (41') to said bed leg member (35'), said bearing assembly (70) including a first annular non-flexible race (71") connected to and extending downwardly from said base leg member (41') and a second annular race (72") slidably connected to and extending upwardly from said bed leg member (35) and positioned adjacent and spaced-apart from said first race (71"), said first and second annular races (71", 72") each having an opposingly facing channel (73, 74) positioned therein, first and second spaced-apart pairs of annular wire tracks (81a-81d) respectively positioned in said channel (73) of said first race (71") and in said channel (74) of said second race (72"), and a plurality of bearing balls (83) positionally supported by and between said first and second pairs of annular wire tracks (81a-81d) so that said cylinder base (40) freely rotates about said bed member (30); and thermal-expansion compensating means integrally formed with said second race (72") and said bed member (30) for compensating for thermal expansion in said cylinder base (40) during heating and cooling thereof, said compensating means including a connector (75') slidably connecting said second race (72") to said bed leg member (35'), a non-flexible bed flange (39') integrally formed with said bed leg member (35'), extending upwardly from said bed leg member (35'), and positioned closely adjacent and abuttingly engaging said second race (72"), a channel (79) formed in said second race (72") and extending upwardly from said bed leg member (35'), and a flexible race flange (72b") positioned between said upwardly extending channel (79) and said non-flexible bed flange (39') so that said second race (72") slidably moves about said connector (75') responsive to heating and cooling of said cylinder base (40) and thereby moves said flexible race flange (72b"). A circular knitting machine (20) as defined in claim 14, wherein said first non-flexible race (71") includes a body portion integrally formed with said base leg member (41') and having a lower flange, an upper flange member (77') detachably connected to said body portion, said lower flange and portions of said upper flange member (77') being respectively positioned along upper and lower ends of said channel (73) for retaining said first pair of wire tracks (81a, 81b) therein, and a fastener (76') adjustably connecting said upper flange member (77') to said body portion. A circular knitting machine (20) as defined in claim 14, wherein said connector (75') of said thermal compensating means is a pin comprising an upper end portion (75a') and a lower end portion (75b', 75c'), said upper end portion (75a') being positioned within said bed leg member (35') and said lower end portion (75b', 75c') positioned within said second race (72"), said lower end portion (75b', 75c') having a smaller circumference than said upper end portion (75a). A circular knitting machine (20) as defined in claim 11 or in claim 14, wherein at least two of said plurality of bearing balls (83a', 83b') have different diameters. A circular knitting machine (20) as defined in claim 11 or in claim 14, wherein said wire tracks (81a'-81d') each have a non-circular cross-section. A circular knitting machine (20) as defined in claim 11 or in claim 14, wherein said bearing assembly (70) further comprises four stop members (85) each respectively positioned closely adjacent each of said wire tracks (81a-81d) and adapted for stopping rotation of said wire tracks (81a-81d). A bearing assembly (70) adapted for connecting to and positioning between a bed member (30) and a base of a needle cylinder (60) of a circular knitting machine (20), said bearing assembly (70) comprising: a first non-flexible race adapted to connect to a base (40) of a needle cylinder (60) of a circular knitting machine (20); a second non-flexible race adapted to connect to a bed member (30) of a circular knitting machine (20), said second race (72) being positioned adjacent and spaced-apart from said first race (71), said first and second races (71, 72) each having an opposingly facing channel (73, 74) positioned therein; first (81a, 81b) and second (81c, 81d) spaced apart pairs of annular tracks respectively positioned in said channel (73) of said first race (71) and in said channel (74) of said second race (72); a plurality of bearing balls (83) positionally supported by and between said first (81a, 81b) and second (81c, 81d) pairs of annular tracks so that the base (40) of the needle cylinder (60) freely rotates about the bed member (30); and thermal-expansion compensating means either integrally formed with the base of the needle cylinder (60) and positioned closely adjacent said first race (71) for compensating for thermal expansion in the base (40) during heating and cooling thereof, said compensating means including a connector (75) slidably connecting said first race (71) to the base (40) and a flexible base flange (43) integrally formed with the base (40) and positioned closely adjacent said first race (71) so that said first race (71) slidably moves about said connector (75) responsive to heating and cooling of the base of the needle cylinder (60) and thereby moves said flexible base flange (43) or integrally formed with the bed member (30) and positioned closely adjacent said second race (72) for compensating for thermal expansion in the base (40) during heating and cooling thereof, said compensating means including a connector (75) slidably connecting said second race (72) to the bed member (30) and a flexible bed flange (39) integrally formed with the bed member (30) and positioned closely adjacent said second race (72) so that said first race (71) slidably moves about said connector (75) responsive to heating and cooling of the base (40) of the needle cylinder (60) and thereby moves said flexible bed flange (39). A bearing assembly (70) as defined in claim 20, wherein said second non-flexible race (72) includes a body portion integrally formed with said bed member (30) and having a lower flange, an upper flange member (177) detachably connected to said body portion, said lower flange and portions of said upper flange member (177) being respectively positioned along upper and lower ends of said channel (74) for retaining said second pair (81c, 81d) of tracks therein, and a fastener (176) adjustably connecting said upper flange member (177) to said body portion. A bearing assembly (70) as defined in claim 21, wherein said upper flange member (177, 277) is adapted for adjusting the positioning of one of said pairs of tracks, and wherein said fastener (176, 276) adjustably connecting said upper flange member (177, 277) to said body portion extends to and through a lower end portion of said bed member (30) for providing easier access to adjustably position said tracks (81c, 81d). A bearing assembly (70) as defined in claim 20, wherein said first non-flexible race (71) includes a body portion integrally formed with the base (40) of the needle cylinder (60) and having a lower flange, an upper flange member (77) detachably connected to said body portion, said lower flange and portions of said upper flange member (77) being respectively positioned along upper and lower ends of said channel (73) for retaining said first pair of wire tracks (81a, 81b) therein, and a fastener (76) adjustably connecting said upper flange member (77) to said body portion. A bearing assembly (70) as defined in claim 20, wherein said connector (75) of said thermal compensating means comprises a pin having an upper end portion (75a) and a lower end portion (75b, 75c), said upper end portion (75a) being positioned within said cylinder base (40) and said lower end portion (75b, 75c) positioned within said first race (71), said lower end portion (75b, 75c) having a smaller circumference than said upper end portion (75a). A bearing assembly (70) as defined in claim 20, wherein said connector (75) of said thermal compensating means comprises a pin having an upper end portion (75a) and a lower end portion (75b, 75c), said upper end portion (75a) being positioned within the base (40) and said lower end portion (75b, 75c) positioned within said second race (72), said lower end portion (75b, 75c) having a smaller circumference than said upper end portion (75a). A bearing assembly (70) as defined in claim 20, wherein at least two of said plurality of bearing balls (83a', 83b') have different diameters. A bearing assembly (70) as defined in claim 20, wherein said first and second tracks each comprise a pair of annular wire tracks (81a'-81d') having a non-circular cross-section. A bearing assembly (70) as defined in claim 20, further comprising four stop members (85) each respectively positioned closely adjacent each of said tracks (81a-81d) and adapted for stopping rotation of said tracks (81a-81d).

Inventors: TSUCHIYA KOJI, TSUCHIYA, KOJI
Applicants: PRECISION FUKUHARA WORKS LTD, PRECISION FUKUHARA WORKS, LTD
Application year: 1994
Main classification: D04B15
IPC codes: D04B15, F16C19, F16C25, F16C33